|Company||Market Cap (USD)|
|Union Pacific||$128.84 B|
|Canadian National Railway Company||$81.31 B|
|Canadian Pacific Railway Limited||$70.14 B|
|CSX Corporation||$64.92 B|
|Norfolk Southern Corporation||$57.49 B|
The market capitalization of a company, more simply referred to as "market cap", is the total market value of a publicly traded company's outstanding shares. It is often considered as a key indicator of what a company is worth.